RFID devices typically contain an integrated circuit chip and an antenna that are connected together to form an electrical circuit that responds to certain transmitted radio frequency (RF) signals. The integrated circuit chip has very small attachment points, commonly referred to as pads, to which the antenna must be electrically connected. Such pads are typically square surfaces with less than 100 μm per side. Antennas used in RFID applications typically have conductors that must be connected to the pads of the integrated circuit chip that have widths of much greater than 100 μm. This difference in relative size makes the manufacture of RFID devices difficult.
As a manufacturing aid, an intermediate fabrication step is frequently employed where an intermediate component is first formed by attaching the integrated circuit chip to relatively short interfacing conductors that have a first end that is much larger than 100 μm and a second end that is sized to accommodate the smaller pads of the integrated circuit chip. This intermediate component that includes the chip and the interfacing conductors is commonly referred to as a strap. Particular strap embodiments are commercially available from a number of sources and are typically sold in large quantities to RFID device manufacturers. In the final manufacturing steps, the strap is attached to the antenna, and both are placed on some form of a substrate. The combination of a strap and an antenna on a substrate is commonly referred to as an inlay. The inlay may later be attached to a label or the like to form an RFID tag that may be attached to a product or item in order to track and/or communicate with the product or item using RF signals.
In many RFID implementations, such as those designed in accordance with the EPCglobal Class 1 Gen 2 specification, the chip/tag is powered by the continuous wave (CW) RF energy provided by an RFID reader device. FCC limits on the CW RF power that may be transmitted dictate certain chip power requirements and operating (maximum) distances. Thus, in such implementations, there is a limitation on the amount of memory that is practically available based on the power limitations. There is therefore room for improvement in the area of transponders and transponder systems, and in particular there is a need for transponders and transponder systems that help to overcome the issues presented by these power limitations.